We have identified a variant human brain protein called Pcl Duarte, which is present in 32% of the normal population with 2.6% being homozygous. In individuals who have committed suicide with manic-depression, depression or alcoholic depression, the frequency of this variant was 64% with 18% homozygous. We believe this represents one of the major genes involved in the affective disorders. Further characterization of this protein is in progress. This protein was discovered by two-dimensional gel electrophoresis of extracts of human brains. The mutant proteins involved in other hereditary neurological disorders such as Huntington' disease, schizophrenia, and tuberous sclerosis are being searched for using this same technique. The membrane proteins and membrane transport properties of fibroblast cells from individuals with Huntington' disease, schizophrenia, manic depression, Turette syndrome, Tuberous sclerosis and other hereditary neurological diseases are being studied.